This application requests funds for the renovations and equipment needed to construct a functional P3 containment facility at the Institute for Cancer Research. The facility has been designed so that it can be used by two research groups simultaneously. On a time allotment basis it should be adequate for the needs of the entire Institute staff. There are several laboratories at the Institute in which recombinant DNA technology is being used or in which use is projected in the next few years. Dr. Robert P. Perry and his associates are using recombinant DNAs to study the synthesis and processing of various mammalian messenger RNAs, including those coding for mouse immunoglobulins. Together with Dr. Martin Weigert, Dr. Perry has also planned experiments in which recombinant DNAs will be used to study the structural organization of the immunoglobulin genes and the mechanisms for the generation of antibody diversity. Dr. Susan Astrin intends to use cloned segments of DNA containing avian viral sequences to study the control of expression of endogenous viral genes. Dr. Lawrence A. Loeb is planning to clone segments of normal human lymphocyte DNA to use as probes for isolating homologous segments of DNA from human leukemic cells. Dr. John Taylor is planning to use recombinant DNA methodologies to further his studies of RNA tumor viruses. The above studies require P3 physical containment and either EK2 or EK3 biological containment. In addition, there are several laboratories working with invertebrates, whose cloning experiments may be performed under P2 (EK1) containment conditions. These include Drs. Kenneth Tartof and George Rudkin, who are studying gene organization and gene expression in Drosophila; Dr. Donald Weeks, who is studying gene regulation in Chlamydomonas; and Dr. Martin Nemer, who is studying embryonic development in the sea urchin. Although these groups do not require P3 containment, the facility will be available to them during periods when it is not being used for P3 experiments. This arrangement will enable us to make maximum use of the facility resources and to have considerable flexibility in our experimental protocols.